Ingot for and method of making composite articles



July 29, '1947. 1.. w; TOWNSEND I 2,424,779

I INGOT FOR AND MET HOD OF MAKING COMPOSITE ARTICLES I Filed A ril 16,1945 .J i -Z 8 l I 20 Z INVENTOR 6 ATTORNEYS 19 A ig sbon/fl 7514029917011:44:, AM 7 a '1;

Patented .iui ze, 1947 'INGOT 'FOR AND METHOD OF MAKING I COMPOSITEABTICLES Leyshon W. Townsend, Washington, Pm, asaignor to Jessop SteelCompany, W corporation of Pennsylvania Application April 16, 1945.Serial No. 588,611

This invention relates to the manufacture of composite or bimetallicstock in the form of bars or strips for the production of cutting toolsof various types such as lathe and plainer tools. saws and the likecomprising a body of a cheaper and softer metal such asordinary orlightly alloyed steel and a smaller portion of a harder metal such ashigh speed steel, high carbon, high chrome steel and the like, thelatter being permanently'welded to the former so as to form one or bothof the narrower faces'of the generally flat bar or strip. The presentinvention relates more particularly to an ingot having embedded thereinat least one insert bar of particular cross sectional shapeanddimensions, the insert bar of the present invention being animprovement over the insert bar disclosed in Trembour Patent No.1,952,002. I have found that superior composite articles can be madefrom the ingot if the insert bar has the cross sectional shape anddimensions hereinafter more fully described. I

produce a better bond between the insert bar of high speed steel and thebody of plain carbon steel. The composite article isalso of greaterstrength, i. e. is more shatterproof and comemies are eifectedjn theproduction of the com-- posite article due'to the shape and dimensionsof the insert bar.

In the accompanying drawings which illustrate a preferred crosssectional shapeand diof a strip formed by severing'the band along thedotted lines of Figure 2; and

Figure 4 is a cross section of the insert bar,

, placed in a mold 3 z which preferably stands vertically and plaincarbon steel 4 is cast about this figure showing the preferred shape anddimensions of the insert bar.

Before referring specifically to the cross sectional shape anddimensions 'of the insert bar 'ing a body of plain carbon steelandanedge of high speed steel can be made. Referring to Figure 1, insert bars2 of high speed steel are the inserts in order to completely envelopethem. Before casting the plain carbomsteel about the inserts, theinserts are suitably cleaned, and if desired electrolytically platedwith iron in order to increase the bonding action between the plaincarbon steel andthe high speed steel inserts. Although in Figure 1 Ihave shown only two insert-bars 2, it will be understood that a greateror less number of insert bars may be used. In carrying 'out the processcommercially, it is preferred to .have seven insert bars in a mold. Asuitable mold 3 is 35" long, 24" wide and has a mold cavity which'is 3%"deep. In using this mold, the insert bars'are 3Q long and are spacedtransversely of the mold, a distance of 2%" from each other. The firstinsert bar is spaced 3%" from the side of the mold.

After the plain carbon steel 4 has been cast about the highspeed steelinserts 2, as shown in Figure 1 to form an ingot, the ingot-is removedfrom the mold and is reduced in thickness by applying pressure to thefaces 5 and 5 as byrolling, thereby producing the band I shown in Figure,2. At this stage in the process the inserts 2 .are still completelyenveloped in the plain carbon steel 4. The lower and upper faces 5 and 6are then removed as by grinding to expose the lower and upper faces 8 ofthe inserts and then the handle severed longitudinally as indicated bythe dotted lines 9, thereby providing the strip Ill shown in Figure 3.This strip has a body portion 4 of plain carbon steel and an edge 2 ofhigh carbon steel, the edge and body being firmly welded to each otherby the rolling operation. If a hacksaw blade is to be made from thecomposite article shown in Figure 3, teeth are cut in the high speedsteel edge 2.

The general process as thus far described is disclosed in the Trembourpatent previously mentioned, and no claim is made herein to the proc--Referring more particularly to Figure 4, the insert bar- 2 has a flattop surface i5 and a. fiatbottom surface it. The sides ii and i8 aresloping and diverge from the top t5 toward the mid portion of the insertbar. Likewise the sides [9 and 20 are sloping and diverge from thebottom i6 toward the mid portion of the insert bar.- Thesloping sidesll, l8, l9 and 20, instead of being extended to meet each other,terminate short of the mid portion of the insert, the tersert bar,amid-the embddiment shown this an- 2| and 2 3 orbetween points 22 and24. is not less than 1'6" and not more than 5 3 of the height H of theinsert bar. 1

. which are uperior froinithe standpoint of bondgle X is about 12, thatis, the angle X between Y the sloping side I! for instance and thevertical line 25 is approximately 12. :According. to this invention,this angle should be not less than and not more than 15.

A projection formed by the surfaces 2},21 and i It lies on each side ofthe cross section of the insert bar. The sides 26 and 28 slope at agreat-' By employing insert bars of the shape and dimensions hereindescribed, composite-articles .ing action between the insert and basematerial, shatterproof qualities and economy in manufacture areobtained.

The invention, is not limited to the exact di- "mensions or shapeillustrated or described but may be otherwise embodied or practicedwithin 7 the scope of the following claims.

er angle to the vertical than 'the' sidesi'l, 18y

I! and 20. In other words the angle Y between the surface 28 and thevertical line 2-9 is greater than the angle x but is less than 90. I Inthe embodiment illustratedin Figure 4, the projections formed by thesesurfaces 26, 21 and 28 extend outwardly beyond the points 2! and 23 orthe points 12 and 24 a, distance of %",'this distance being designatedby Z. According to the invention, this distance Z should not be lessthan'i' or more than V2 the vertical distance between the points 2| and23. v

The distance M which is the vertical distance between the points 2| and23 should be not less than and should be not more than /3 of the totalheight H of the insert The ratio of total height H of insert bar tototal width W or insert bar should be between 15:1 and 3:1, preferablyabout 2:1. If the ratio of height to width is too great, the insert barstend to turn 7 over or buckle in rolling the ingot. containing the bars.It has been found that these objectionable tendencies may be overcome bymaintaining the .ratio of height to width as above specified. On

the other hand if the ratio of height to width of insert bar is toosmall, the composite article after rolling is such that the high speedsteel insert portion (2 of Figure 3) extends so far into the bodyportion 4 of plain carbon steel that the articleis not shatterproof andmay break in use. Another disadvantage of having the ratio of height towidth too small is that it increases the cost of composite articles.

As previously stated, the value of the angle X is very important. If thewidth of the top 15 and bottom iii are kept constant, increasing theangle X increases the .width W. This increase in angle X is desirablefrom certain standpoints and undesirable from other standpoints. Itincreases the bonding action between the plain carbon steel and the highspeed steel insert duringrolling. However, this increased bonding isaccompanied by anincreased tendency of the composite tool to shatter inuse. Furthermore, the cost of the composite article is lncrease d byincreasing the angle X. I have found that in order to obtain the proper.bonding action between the insert and the body material while stillretaining sufiicient shatterprooj properties in the composite article,the angle X should be not less than 10 nor more-than 15.

I have found that in order to obtain good bondshould be not less than3%" nor more than A;

the vertical distance M. Further improvements in results. are obtainedwhen the dimension M,

which is the vertical distance between the points metal and an edge ofrelatively hard metaL'said- Iclaim":

posite strips having a body of relatively soft ingot comprising at leastone insert bar of relatively hard metal embedded inand completelyenclosed by an envelope of relatively soft metal, each insert bar beingsolid and symmetrical in cross section andhaving a flat top and bottom.-sloping sides diverging from both top and bottom toward but stoppinshort of the mid Portion of the insert, the angle of slope of the sidesbeing between 10 and 15, and a projection on each side of the crosssection connecting the adjacent ends of the sloping sides, eachprojection extending outwardly'beyond the sloping sides a dis-' tancenot less than and not more than /2 the vertical distance between theadjacent ends of the sloping sides, the insert having a ratio of heightto width between 1.5:]. and 3: 1.

2. An ingot for use in the manufacture of composite strips having a bodyof relatively soft metal and an edge of relatively hard metal, saidingot comprising at least one insert bar of relatively hard metalembedded in and completely enclosed by an envelope of relatively softmetal, each insert bar being solid and symmetrical in cross section andhaving a not top andbottom, sloping sides diverging from both top andbottom toward but stoppingv short of the mid portion of the insert, theangle of slope of the sides being between 10 and 15, and a projection oneach side of the cross section connecting the adjacent ends or thesloping sides, each projection extending outwardly beyond the slopingsides a distance not less than it" and not more than' A; the verticaldistance between the adjacent ends of the sloping sides, the inserthaving a ratio ofv height to width between 1.5: 1 and 31, the verticaldistance between the adjacent ends of the sloping sides being not lessthan 1 and not more than of the height of the insert.

3. An ingot for use in the manufacture of composite strips having a bodyof relatively soft metal and an edge of relatively hard metal, saidingot comprising at least one insert bar ofrelatively hard metalembedded in and completelyenclosed by an envelope of relatively softmetal, each insert bar being solid and symmetrical in cross section andhaving a flat top and bottom, sloping sides diverging from both top andbottom toward but stopping short of the mid portion of the insert, theangle of slope of the sides being be-- tween 10 and 15, and a projectionon each side of the cross section connecting the adjacent ends of theslopin sides, each projection extending outwardly beyondthe slopingsides a distance not less than and not more than /2 the verticaldistance between the adjacent ends of the sloping sides, each projectionhaving two sloping portions converging toward the mid portion of theinsert, the slope of the sloping portions of 1. An ingot for use in themanufacture of comthe. projections being greater than the slope of thesloping sides of the insert but less than 90, the insert having a ratioof height to width between 1.5:1 and 3:1.

4. An ingot for use in the manufacture of composite strips having a bodyof relatively soft metal and an edge of relatively hard metal, saidingot comprising at leastone insert bar of relatively hard metalembedded in and completely enclosed by an envelope of relatively softmetal, each insert bar being solid and symmetrical in cross section andhaving a flat top and bottom, sloping sides diverging from both top andbottom toward but stopping short. of the mid portion of th insert, theangle of slope of the sides being between and and a projection on eachside of the cross section connecting the adjacent ends of the slopingsides, each projection extending outwardly beyond the sloping sides adistance not less than 3 and'nOt more than /2 the vertical distancebetween the adjacent ends of the sloping sides, each projection havintwo sloping portions converging toward the mid portion of the insert,the slope of the sloping portions of the projections being greater thanthe slope of the sloping sides of theinsert but lessthan 90, the inserthaving a ratio of height to width between 15:1 and 3:1, the verticaldistance between the adjacent ends of the sloping sides being not lessthan 1%" and not more than /3 of the height of the insert.

5. The method of making composite strips having a body of relativelysoft metal and an edge of relatively hard metal, which comprisesproviding an ingot comprising at least one insert bar of relatively hardmetal embedded in and completely enclosed by an envelope of relativelysoft metal, each insert bar being solid and symmetribottom toward butstopping short of the mid portion of the insert, the angle of slope ofthe sides being between 10 and 15, and a projection on each side of thecross section connecting the adjacent ends of the sloping sides eachprojection extending outwardly beyond the sloping sides a distance notless than 5% and not more than the vertical distance between theadjacent ends of the sloping sides, the insert having a ratio of heightto width between 1.5:1 and 3:1, reducing the thickness of the ingot toform a band and severing the band longitudinally through the insertbars.

- LEYSHO-N W. TOWNSEND.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,060,858 Flynt Nov. 17, 1936155,180 Coes Sept. 22, 1874 377,318 Marshall -1 Sept. 22, 1874 1,952,002Trembour Mar. 20, 1934

